Functional characterization of BdB1, a well-conserved carboxylesterase among tephritid fruit flies associated with malathion resistance in Bactrocera dorsalis (Hendel)

Author(s):  
Luo-Luo Wang ◽  
Xue-Ping Lu ◽  
Guy Smagghe ◽  
Li-Wei Meng ◽  
Jin-Jun Wang
Author(s):  
Peter A Follett ◽  
Fay E M Haynes ◽  
Bernard C Dominiak

Abstract Tephritid fruit flies are major economic pests for fruit production and are an impediment to international trade. Different host fruits are known to vary in their suitability for fruit flies to complete their life cycle. Currently, international regulatory standards that define the likely legal host status for tephritid fruit flies categorize fruits as a natural host, a conditional host, or a nonhost. For those fruits that are natural or conditional hosts, infestation rate can vary as a spectrum ranging from highly attractive fruits supporting large numbers of fruit flies to very poor hosts supporting low numbers. Here, we propose a Host Suitability Index (HSI), which divides the host status of natural and conditional hosts into five categories based on the log infestation rate (number of flies per kilogram of fruit) ranging from very poor (<0.1), poor (0.1–1.0), moderately good (1.0–10.0), good (10–100), and very good (>100). Infestation rates may be determined by field sampling or cage infestation studies. We illustrate the concept of this index using 21 papers that examine the host status of fruits in five species of polyphagous fruit flies in the Pacific region: Bactrocera tryoni Froggatt, Bactrocera dorsalis (Hendel), Bactrocera latifrons (Hendel), Zeugodacus cucurbitae (Coquillett), and Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). This general-purpose index may be useful in developing systems approaches that rely on poor host status, for determining surveillance and detection protocols for potential incursions, and to guide the appropriate regulatory response during fruit fly outbreaks.


2021 ◽  
Author(s):  
Mohammed E. E. Mahmoud ◽  
Mohammed ◽  
Fathya M. Khamis and ◽  
Sunday Ekesi ◽  

Abstract Fruit flies of the genus Bactrocera are the most damaging pests of horticultural crops, leading to severe economic losses hindered exportation. Bactrocera dorsalis (Hendel) and Bactrocera zonata (Saunders) were reported in Sudan in 2005 and 2011 respectively affecting most of the fruits and vegetables in Sudan threatening income of poor farmers. Only Male Annihilation Technique (MAT) is applied in Sudan to manage the two Bactrocera species. A filed experiment was conducted to evaluate the response of B. dorsalis, B. zonata and Zeugodacus cucurbitae to three food-based attractants using McPhail traps in two sites in Gezira state, Sudan. Also, other trial was undertaken to determine the effect of spray of Mazoferm and Spinosad combination to control B. zonata. The results showed that food-based attractants lured both sexes of the above mentioned fruit flies and females represented (55-86%). At the first site, B. zonata responded in high numbers to Mazoferm followed by Torula yeast and GF-120 respectively while it responded equally to the Mazoferm and Torula yeast in the second site. B. dorsalis responded positively to Mazoferm followed by Torula yeast and GF-120 while Z. cucurbitae was attracted to Mazoferm, GF-120 and Torula for each attractant respectively. Spray of Mazoferm combined with Spinosad significantly reduced population of B. zonata (FTD) population and suppressed infestation level of guava fruits (fruit flies/Kg of fruits) when compared to unsprayed orchard. Bait Application Technique is an environmentally friendly approach that reduces infestation levels, lessen contamination and safeguard produce.


Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 371 ◽  
Author(s):  
Vanessa S. Dias ◽  
Guy J. Hallman ◽  
Olga Y. Martínez-Barrera ◽  
Nick V. Hurtado ◽  
Amanda A. S. Cardoso ◽  
...  

Phytosanitary irradiation (PI) has been successfully used to disinfest fresh commodities and facilitate international agricultural trade. Critical aspects that may reduce PI efficacy must be considered to ensure the consistency and effectiveness of approved treatment schedules. One factor that can potentially reduce PI efficacy is irradiation under low oxygen conditions. This factor is particularly important because storage and packaging of horticultural commodities under low oxygen levels constitute practices widely used to preserve their quality and extend their shelf life. Hence, international organizations and regulatory agencies have considered the uncertainties regarding the efficacy of PI doses for insects infesting fresh commodities stored under low oxygen levels as a rationale for restricting PI application under modified atmosphere. Our research examines the extent to which low oxygen treatments can reduce the efficacy of phytosanitary irradiation for tephritids naturally infesting fruits. The effects of normoxia (21% O2), hypoxia (~5% O2), and severe hypoxia (< 0.5% O2) on radiation sensitivity of third instars of Anastrepha fraterculus (sensu lato), A. ludens (Loew), Bactrocera dorsalis (Hendel), and Ceratitis capitata (Wiedemann) were evaluated and compared at several gamma radiation doses. Our findings suggest that, compared to normoxia, hypoxic and severe-hypoxic conditioning before and during irradiation can increase adult emergence and contribute to advancement of larval development of tephritid fruit flies only at low radiation doses that are not used as phytosanitary treatments. With phytosanitary irradiation doses approved internationally for several tephritids, low oxygen treatments applied before and during irradiation did not increase the emergence rates of any fruit fly species evaluated, and all treated insects died as coarctate larvae. Thus, the findings of our research support a re-evaluation of restrictions related to phytosanitary irradiation application under modified atmospheres targeting tephritid fruit flies.


2016 ◽  
Vol 130 ◽  
pp. 44-51 ◽  
Author(s):  
Luo-Luo Wang ◽  
Xue-Ping Lu ◽  
Li-Wei Meng ◽  
Yong Huang ◽  
Dong Wei ◽  
...  

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